Selectable one-way clutch with common coil unit and axially moveable armature for active strut actuation

Abstract

A bi-directional clutch assembly includes an outer race defining first and second strut pockets, an inner race defining ratchet teeth, a passive one-way clutch including at least two passive struts each supported in a corresponding first strut pocket for pivotal movement relative to the ratchet teeth, passive strut springs for normally biasing the passive struts into engagement with the ratchet teeth on the inner race, and a selectable one-way clutch having at least one active strut supported in the second strut pocket for pivotal movement between a non-deployed position disengaged from the ratchet teeth and a deployed position engaged with the ratchet teeth, and an armature ring fixed for rotation with the outer race and axially moveable between a non-actuated position and an actuated position, in which a strut engagement feature moves the active strut from its non-deployed position to its deployed position.

What is claimed: 
     
       1. A bi-directional clutch assembly comprising:
 a rotary input; 
 a rotary output; 
 an outer race fixed for rotation about an axis with one of the input and the output and defining first and second strut pockets; 
 an inner race fixed for rotation with the other of the input and the output and defining ratchet teeth; 
 a passive one-way clutch including at least two passive struts each supported in a corresponding first strut pocket for pivotal movement relative to the ratchet teeth; 
 passive strut springs for normally biasing the passive struts into engagement with the ratchet teeth on the inner race; and 
 a selectable one-way clutch including at least one active strut supported in a corresponding second strut pocket for pivotal movement between a non-deployed position disengaged from the ratchet teeth and a deployed position engaged with the ratchet teeth, wherein the at least one active strut is biased toward the non-deployed position; 
 an axially moveable armature ring moveable along the axis between a non-actuated position and an actuated position, wherein movement of the armature ring to the actuated position causes movement of the at least one active strut to the deployed position. 
 
     
     
       2. The assembly of  claim 1 , further comprising an annular coil unit fixed to a stationary member, wherein the armature ring moves axially to the actuated position in response to energization of the annular coil unit. 
     
     
       3. The assembly of  claim 2 , wherein the armature ring is fixed for rotation with the outer race. 
     
     
       4. The assembly of  claim 3 , wherein the armature ring includes a strut engagement feature, wherein the strut engagement feature is configured to contact the at least one active strut in response to movement of the armature ring to the actuated position, wherein contact by the strut engagement feature with the at least one active strut causes the active strut to move to the deployed position. 
     
     
       5. The assembly of  claim 4 , wherein the armature ring includes a ring segment overlying the coil unit and a flange segment, wherein the strut engagement feature is attached to the flange segment. 
     
     
       6. The assembly of  claim 4 , wherein the strut engagement feature includes a ramped surface configured to contact the at least one active strut. 
     
     
       7. The assembly of  claim 2 , wherein the coil unit is disposed radially outward from the outer race. 
     
     
       8. The assembly of  claim 1 , wherein the at least one active strut in the deployed position blocks relative rotation between the inner race and the outer race in a first direction, and the passive struts block relative rotation between the inner race and the outer race in a second direction that is opposite the first direction to define a Locked/Locked mode of operation. 
     
     
       9. The assembly of  claim 8 , wherein the at least one active strut in the non-deployed position defines a Freewheel/Locked mode of operation, where the passive struts block relative rotation in the second direction and allow relative rotation in the first direction. 
     
     
       10. The assembly of  claim 1 , wherein the at least one active strut includes a corresponding active strut spring for biasing the at least one active strut to the non-deployed position. 
     
     
       11. The assembly of  claim 1  wherein the passive strut spring is offset relative to a pivot axis of the passive strut to provide a tail-heavy configuration. 
     
     
       12. The assembly of  claim 1 , wherein the armature ring is biased toward the non-actuated position. 
     
     
       13. A method of operating a bi-directional clutch assembly, the method comprising the steps of:
 energizing an annular coil, wherein the annular coil extends circumferentially about an axis; 
 moving an armature ring axially along the axis from a non-actuated position to an actuated position in response to energizing the annular coil; 
 contacting at least one active strut with a strut engagement feature of the armature ring and, in response thereto, pivoting the at least one active strut from a non-deployed position into a deployed position in which the active strut engages ratcheting teeth of an inner race; 
 wherein the active strut is supported in an active strut pocket formed in an outer race for pivotal movement between the deployed position and the non-deployed position; 
 wherein, in the deployed position, the at least one active strut blocks relative rotation about the axis between the inner race and the outer race in a first direction; 
 wherein the bi-directional clutch assembly further includes at least two passive struts supported in passive strut pockets formed in the outer race and biased into engagement with the ratcheting teeth, wherein the at least two passive struts block relative rotation between the inner race and the outer race in a second direction that is opposite the first direction; 
 wherein, when the at least one active strut is in the deployed position, the bi-directional clutch assembly is a Locked/Locked mode of operation in which relative rotation is blocked in both the first and second direction, and when the at least one active strut is in the non-deployed position, the bi-directional clutch assembly is in a Freewheel/Locked mode of operation in which relative rotation is blocked in the second direction by the passive struts and allowed in the first direction. 
 
     
     
       14. The method of  claim 13 , further comprising de-energizing the annular coil and, in response thereto, moving the armature from the actuated position to the non-actuated position, wherein the armature is biased toward the non-actuated position, and pivoting the at least one active strut from the deployed position to the non-deployed position, wherein the at least one active strut is biased toward the non-deployed position. 
     
     
       15. The method of  claim 13 , wherein the armature is fixed for rotation to the outer race, and the annular coil is fixed to a stationary member.